1. Do non ladder players only play with non ladder player?
I mean its kinda obvious question, but will there be 2 different game zone?
Non ladder world / ladder world?
if you are non ladder player, can you duel with ladder player?

2. about the items
it says all possesion will be moved to non-ladder
does it mean everything ( rune, jewl , gems, and charms) will also marked non ladder?

3. how big non ladder will be?
i just started like a month ago, and not familiar with reset thing
so after it is reset, do people still play in non ladder or people move to ladder?
how about the trade?
does trade happen like in ladder ?

4. what should i do now?
now about 2 weeks left on ladder, what should i prepare before season ends?
should i sell all my junks to get as much as ladder-only items?
suggest me anything plz
need help!!!

Gathering ladder runewords is what all the others do as well. Also, there are far less NL players than players on ladder and you need those who have ladder wealth as well. Apart from that, the rich guys already have all they need from the previous 5 ladder resets, so it will be hard to find buyers for anything than ladder runewords with perfect variables... or close to perfect of there's a lot of variation.

If you want to do something with your wealth when it has become NL, get sojs (rich guys organize dclone spawnings with NL sojs) and pgems and crafting runes (rich guys reroll items like crazy). These resources deplete after some time while all the runewords won't get less, except to people abandoning their accounts. I doubt that you can afford many sojs from 3 weeks of playing, so better go for pgems or crafting runes. The more, the better. Whole accounts full of them are OK.

However, cross-trades have become pretty rare. The ratio used to be 1:10 and it will be even worse at the beginning of a ladder season.

Update: Forget about sojs, it seems to be what everybody and his dog is already doing.